Negative numbers help us to model many real world situations.
Table for Jean's tune ups versus profit (Problem 5.2):
*Negative #'s in parentheses in table. Example (800) = -800.
Tune Ups
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
Profit ($)
(800)
(740)
(680)
(620)
(560)
(500)
(440)
(380)
(320)
(260)
(200)
(140)
(80)
(20)
40
100
160
220
280
340
400
A 1. In the table of data you made in problem 5.2, what range of values did you use for the number of tune-ups? The range I chose for the tune-ups was 0 -20. 2. What range of values did you use for the profit? The range I used for the profit was (-800) – 400. B Enter the profit equation into your calculator. Use the number of tune-ups as the x variable and the profit as the y variable. Use your answers to part A to help you decide to adjust the window setting so that you will be able to see the graph of the profit equation. Press GRAPH to display the graph. Make a sketch of the graph you see on the screen.
C How is the break-even point shown on the graph? D Look at the table of data on your calculator. How is the break-even point shown in the table? ** The break-even point isn’t shown in the table; it just shows before and after the breakpoint. This is because after her 13th tune-up, she is still short $20, but after her 14th tune-up, she has $40. This shows that the breakpoint is somewhere between her 13th and 14th tune-up.
MMS
May 5/2010
Math 7B
Big Idea
Negative numbers help us to model many real world situations.
Table for Jean's tune ups versus profit (Problem 5.2):
*Negative #'s in parentheses in table. Example (800) = -800.
The range I chose for the tune-ups was 0 -20.
2. What range of values did you use for the profit?
The range I used for the profit was (-800) – 400.
B Enter the profit equation into your calculator. Use the number of tune-ups as the x variable and the profit as the y variable. Use your answers to part A to help you decide to adjust the window setting so that you will be able to see the graph of the profit equation. Press GRAPH to display the graph. Make a sketch of the graph you see on the screen.
C How is the break-even point shown on the graph?
D Look at the table of data on your calculator. How is the break-even point shown in the table? **
The break-even point isn’t shown in the table; it just shows before and after the breakpoint. This is because after her 13th tune-up, she is still short $20, but after her 14th tune-up, she has $40. This shows that the breakpoint is somewhere between her 13th and 14th tune-up.